1. Field of the Invention
This invention relates to a foldable frame assembly for suspending a machine, such as a sawing, cutting or planing machine, above a ground surface, more particularly to a foldable frame assembly which can be folded and unfolded conveniently and which can be adapted for suspending machines of different sizes.
2. Description of the Related Art
Referring to FIG. 1, a conventional foldable frame assembly 10 is shown to include first and second propping frames 11, 12, a pair of wheels 13, a hydraulic cylinder unit 14, and front and rear carrying frames 15, 16. The first and second propping frames 11, 12 are pivotally connected to each other at middle portions thereof. The first propping frame 11 has an upper end formed as a handle 111, a lower end for mounting the wheels 13, and a middle portion formed with first and second positioning holes 112, 113 and two barrier pins 114 adjacent to the first and second positioning holes 112, 113, respectively. The second propping frame 12 has an upper end formed as a transverse rod 121, and a lower end provided with a footpad 122 for resting on the ground surface. The hydraulic cylinder unit 14 is disposed to serve as a damper for folding and unfolding the first and second propping frames 11, 12. The front and rear carrying frames 15, 16 are disposed for supporting a machine 100. The front carrying frame 15 has a lug portion 151 which is mounted securely on the first propping frame 11 by a positioning pin 152 that extends through the lug portion 151 and that engages the first positioning hole 112 so as to lock the first and second propping frames 11, 12 in an unfolded position. The rear carrying frame 16 has a hook portion 161 engaging the transverse rod 121. When it is desired to fold the frame assembly 10 for moving purpose, the user has to hold the machine 100 with one hand and remove the positioning pin 152 from the first positioning hole 112 with the other hand so that the machine 100 can swing downwardly about the transverse rod 121 by virtue of its own weight. At the same time, the user has to fold the first and second propping frames 11, 12 and register the lug portion 151 with the second positioning hole 113 so as to permit insertion of the positioning pin 152 into the second positioning hole 113. However, it is difficult for the user to fold the first and second propping frames 11, 12 because his both hands are already occupied. Moreover, during the folding operation, the frame assembly 10 tends to move undesirably because of the wheels 13, which may result in danger to the user. Furthermore, the conventional frame assembly 10 is only suitable for supporting and carrying machines of a fixed dimension.